In a process of manufacturing a semiconductor substrate (hereinafter, referred to simply as a “substrate”), conventionally, various processings are performed on a substrate having an insulating film such as an oxide film or the like thereon by using a substrate processing apparatus. By supplying a processing liquid onto a substrate having a surface on which a resist pattern is formed, for example, a processing such as etching or the like is performed on the surface of the substrate. Further, after etching or the like is finished, a process of removing the resist from the substrate is also performed.
In a substrate processing apparatus disclosed in Japanese Patent Application Laid-Open No. 2009-200365 (Document 1), before a processing using a processing liquid such as an SPM (sulfuric acid/hydrogen peroxide mixture) liquid or the like is performed, a liquid having electrical conductivity lower than that of the processing liquid is supplied to a processing area on a substrate and then the processing liquid is discharged to the processing area with the liquid existing therein. It is thereby possible to prevent any local damage of the substrate due to the contact made between the substrate and the processing liquid. The local damage of the substrate refers to local destruction of a field oxide film or a gate oxide film in the processing area, and the destruction is caused by bringing the processing area on the substrate into contact with the processing liquid which is electrically charged by the frictional electrification phenomenon between the processing liquid and a processing liquid nozzle.
Japanese Patent Application Laid-Open No. 2007-134673 (Document 2) discloses a technique in which before supplying a processing liquid such as concentrated sulfuric acid or the like to a processing area on a wafer, a liquid such as carbon dioxide water or the like having an electrical resistivity value lower than that of the processing liquid is supplied to the processing area and the processing liquid is discharged to the processing area with the liquid existing therein. It is thereby possible to prevent electrification caused by the electrostatic friction phenomenon which occurs when the processing liquid comes into contact with the processing area.
Japanese Patent Application Laid-Open No. 2007-214347 (Document 3) discloses a technique used in a cleaning apparatus for electronic devices, to eliminate static electricity existing on a surface of a substrate or in a processing liquid nozzle by supplying ionized vapor to the surface of the substrate or the processing liquid nozzle. In a substrate processing apparatus disclosed in Japanese Patent Application Laid-Open No. 2011-103438 (Document 4), before a liquid process on a circuit-forming surface of a substrate, a static elimination process of discharging an anti-static liquid toward a surface opposite to the circuit-forming surface of the substrate.
On the other hand, Japanese Patent Application Laid-Open No. 2004-158588 (Document 5) discloses a substrate processing apparatus which removes organic matter adhering to a surface of a substrate by supplying a removal liquid onto the surface of the substrate. The substrate processing apparatus includes a temperature control part for adjusting the temperature of the substrate so that a difference between the temperature of the substrate and the temperature of the removal liquid supplied onto the substrate may be within a predetermined range. As an example of the temperature control part, used is a fluid supply part for supplying a fluid whose temperature is adjusted onto a back surface of a substrate held by a holding rotating part.
A substrate to be processed by a substrate processing apparatus is subjected to a drying process such as dry etching, plasma CVD (Chemical Vapor Deposition), or the like, before being loaded into the substrate processing apparatus. In such a drying process, since electric charges are generated in a device, the substrate which is electrically charged is loaded into the substrate processing apparatus. Then, in the substrate processing apparatus, when a processing liquid having low electrical resistivity, such as an SPM liquid, is supplied onto the substrate, the electric charges in the device sharply move from the device to the processing liquid (in other words, the electric charges are discharged into the processing liquid) and damage may be caused in the device by heat generation due to the movement of the electric charges. Then, it is thought to be effective to remove static electricity from the substrate by using an ionizer before supplying the processing liquid onto the substrate, but when the amount of electrostatic charges on the substrate is too large, it is hard to efficiently remove static electricity from the substrate.